Inkjet printing propels droplets of printing fluid onto media to create an image on a substrate in a 2D printing device, or a layer of an object in a build material in a 3D printing device. For example, an inkjet printer may comprise a printhead comprising an ink drop generator, or plural ink drop generators, that propel the printing fluid through an aperture, or nozzle, to eject a droplet of printing fluid onto the media.
Reliable printing operation in part requires reliable operation of the nozzles. If a nozzle were to malfunction, printing fluid may not be properly ejected, which can have a negative impact on the quality of the printed image or object. Failure mechanisms of the nozzles may include a malfunction of the resistive element, a blockage of an ink supply line, a blockage in the firing chamber, and/or a blockage in the aperture.